METHOD FOR MANUFACTURING A THREE-DIMENSIONAL FORMED STRUCTURE IN POLYAMIDE TEXILES

Abstract

 Method for manufacturing a three-dimensional formed structure from a textile fabric, comprising the steps of
(a) providing a textile fabric comprising polyamide;
(b) contacting the textile fabric with a treatment solution wherein the treatment solution comprises a mixture of CaCl₂, EtOH and H₂O, wherein the CaCl₂ content is > 6 mol%, the EtOH content is < 25 mol%, the molar ratio between CaCl₂ : EtOH : H₂O is between 1 : 0.6 - 2 : 3.4 - 7 and the H₂O/EtOH molar ratio is > 2.5. for at least 1 second and at most 4 hours by immersion or for at least 1 s and at most 5 minutes by spraying;
(c) squeezing of the treatment liquid from the fabrics to adjust the solvent content in the fabrics;
(d) consolidating the textile fabric for 1 s to 60 minutes while the textile fabric is still containing the treatment solution by increasing the temperature of the textile fabric to a temperature of between 10 °C to 120 °C with the provision that the temperature is at least 100 °C below the melting point of the polyamide and by forming the textile fabric in the desired three-dimensional structure;
(e) quenching the treatment solution while the formed textile fabric still contains treatment solution by adding water and/or by evaporating ethanol out from the fabric;
(f) isolating the formed textile fabric followed by washing and drying.

Description

[0001] The present invention relates to a method for manufacturing a three-dimensional formed structure. Furthermore, the invention relates to an article comprising a three-dimensional formed structure.

Background of the invention

[0002] Polyamide 66 (or PA 66 or PA 6.6) is one of the most widely spread polymers in the textile industry. It has excellent mechanical properties and is inert towards most organic solvents. Known solvents require toxic and harsh conditions such as formic acid, cresol and phenol. Furthermore, polyamide 66 exhibits a low surface energy, which impedes the application in products requiring interfacial adhesion, such as textile composites. Surface treatments such as plasma treatment, grafting and surface roughening with solvents are used. The interaction of the carbonyl group of polyamide 66 and Lewis acids enables Lewis acid-base complexation and dissolution of polyamide 66 in solutions containing GaCl₃, AlCl₃, CaCl₂, BF₃, or BCl₃. Complexation of polyamide suppresses the hydrogen bonding between the polymer chains and causes dissolution of the polyamide. The use of CaCl₂/MeOH solutions to dissolve polyamide has been shown by Sun et al., who supposed a complexation mechanism (Sun et al., Study on the mechanism of nylon 66 dissolving process using CaCl2/MeOH as the solvent. Chin. J. Polym. Sci., 1994). Li et al. used CaCl₂/EtOH to modify the surface roughness of Kevlar fibres (Li et al., Effect of Calcium Chloride on the Surface Properties of Kevlar Fiber, J. Appl. Polym. Sci, 2015).

[0003] The effect of swelling of polyamide 6.6 in a mixture of CaCl₂/H₂O/EtOH is disclosed in EP 3 378 988 A1. The polyamide fibre is exposed to a mixture of CaCl₂/H₂O/EtOH, wherein the CaCl₂ content is > 6 mol%, the EtOH content is < 25 mol% and the H₂O/EtOH molar ratio is > 2.5. Further investigations on the CaCl₂/H₂O/EtOH solvent system are described in Rietzler, B., T. Bechtold and T. Pham (2018) "Controlled Surface Modification of Polyamide 6.6 Fibres Using CaCl2/H2O/EtOH Solutions", Polymers 10(2): 207. Different compositions of CaCl₂/H₂O/EtOH and their effect on polyamide 66 fibres are investigated and the kinetics of the dissolution and swelling are reported. In Rietzler, B., T. Bechtold and T. Pham (2019). "Spatial structure investigation of porous shell layer formed by swelling of PA66 fibres in CaCl2/H2O/EtOH mixtures." Langmuir, 35(14): 4902-4908, the structure of the porous shell layer formed by swelling of the fibres in the solvent mixtures is investigated with AFM-IR.

Short Description of the Invention

[0004] The inventors of the present invention have now found that treatment of textile fabric comprising polyamide with CaCl₂/H₂O/EtOH mixtures in a defined concentration range, for a defined exposure time and a defined temperature yields modified polyamide with specific properties, in particular, it was found that textile fabrics treated under such conditions allow the formation of articles with a three-dimensional structure. Furthermore, the invention allows to form three-dimensional structures having soft and hard segments without any additional joining steps.

[0005] Accordingly, the invention relates to a method for manufacturing a three-dimensional formed structure from a textile fabric, comprising the steps of

(a) providing a textile fabric comprising polyamide;

(b) contacting the textile fabric with a treatment solution, wherein the treatment solution comprises a mixture of CaCl₂, EtOH (ethanol) and H₂O, wherein the CaCl₂ content is > 6 mol%, the EtOH content is < 25 mol%, the molar ratio between CaCl₂ : EtOH : H₂O is between 1 : 0.6 - 2 : 3.4 - 7 and the H₂O/EtOH molar ratio is > 2.5. for at least 1 second and at most 4 hours by immersion or for at least 1 s and at most 5 minutes by spraying;

(c) squeezing of the treatment solution from the fabric to adjust the solvent content in the fabric;

(d) consolidating the textile fabric for 1 s to 60 minutes while the textile fabric is still containing the treatment solution while the temperature of the textile fabric is kept between 10 °C to 120 °C with the provision that the temperature is at least 100 °C below the melting point T_m of the polyamide and by forming the textile fabric in the desired three-dimensional structure;

(e) quenching the treatment solution while the formed textile fabric still contains treatment solution by adding water and/or by evaporating ethanol out from the fabric;

(f) obtaining the formed textile fabric followed by washing and drying.

[0006] The steps are performed in the described order.

[0007] Surprisingly, the treatment of a flowing fabric comprising polyamide with a mixture of CaCl₂/EtOH/H₂O as described above allows forming the fabric into a three dimensionally shaped article. The stability of the formed textile fabric is surprising in view of the prior art such as EP 3 378 988 A1 which describes surface modification lowering the overall stability of the polyamide. The present invention now shows that a treatment solution with a mixture of CaCl₂/EtOH/H₂O under well-defined conditions results in a three-dimensional stable article. Furthermore, when applying the septs (a) to (f) on selected parts of a fabric, a combination of soft segments and hard three dimensionally shaped structures can be formed without any additional joining steps between those segments.

[0008] The textile fabric is a knitted fabric or woven fabric, comprising interlacing threads or a nonwoven. The basis weight of the textile fabric is preferably in the range between 10 and 220 g/m², more preferably 30 and 180 g/m². Such a textile fabric has no dimensional stability before treatment. However, after the treatment according to the invention, the basis weight remains the same (preferably in the range between 10 and 220 g/m², more preferably 30 and 180 g/m²) but it has dimensional stability.

[0009] Preferably, the contacting step of the fabric sample in a treatment solution of CaCl₂/EtOH/H₂O is carried out for at least 10 s and at most 60 minutes.

[0010] More preferably, the contacting step of the fabric sample in a treatment solution of CaCl₂/EtOH/H₂O is carried out and immediately followed by squeezing and consolidating.

[0011] When spraying technique of the treatment solution of CaCl₂/EtOH/H₂O on the fabric is applied, the spraying time is preferably at least 5 s and at most 2.5 minutes immediately followed by squeezing and consolidating steps.

[0012] Preferably, the molar ratio between CaCl₂: EtOH : H₂O is approximately 1 : 1.5 : 5.5.

[0013] The contacting step of the of the fabric in the treatment solution can be immersion with a squeezer, spraying, dipping, pressing etc. Preferably, the contacting step of the fabric sample in the treatment solution of CaCl₂/EtOH/H₂O is carried out for approximately 2 minutes.

[0014] During squeezing of the treatment solution (step (c)) from the fabrics to adjust the solvent content in the fabrics also pressure can be applied to pre-form the shape of the textile fabric.

[0015] The temperature in step (d) is between 10 °C to 120 °C with the provision that the temperature is at least 100 °C below the melting point of the polyamide and can involve heating and/or cooling depending on the conditions.

[0016] Obtaining the formed textile fabric in step (f) can involve isolating of the formed fabric.

[0017] Different ways of forming are possible. One preferred way of forming includes applying a pressure of between 0.1 bar and 100 bar, preferably 2 to 12 bar to the textile fabric.

[0018] In a very preferred embodiment only a selected part of the textile fabric sample comprising polyamide is formed. This allows the formation of an article, comprising areas with flexible textile fabric and formed, stable textile fabric. Thus, articles comprising soft segments and hard three dimensionally shaped structures can be formed without any additional joining steps between those segments.

[0019] In a preferred embodiment the polyamide (PA) is an AB polymer, an AA/BB polymer or a mixture thereof, wherein the AB polymer comprises the following structure units -[NH-(CH₂)_x-CO]_n- and the AA/BB polymer comprises the following structure units -[NH-(CH₂)_x-NH-CO-(CH₂)_y-CO]_n-.

[0020] PA are usually categorized as AB polymers and AA/BB polymers. PA of the AB polymer type comprise the following structure units

         -[NH-(CH₂)_x-CO]_n-.

[0021] For x = 5 ist the PA type is PA 6, because the repetitive unit has 6 carbon atoms.

[0022] PA of the AA/BB polymer type comprise the following structure units.

         -[NH-(CH₂)_x-NH-CO-(CH₂)_y-CO]_n-.

[0023] In case x = 6 and y = 4 the PA type is PA 6.6, since the first repetitive units comprises 6 carbon atoms and the second repetitive unit comprises 6 carbon units.

[0024] While the invention extends to the known PA types, the preferred PA types are PA 6 and PA 6.6. The most preferred one is PA 6.6.

[0025] PA 6.6. has a melting point T_m of 264 °C.

[0026] The invention further relates to a textile fabric comprising a three-dimensional formed structure obtainable by a method as described above.

[0027] Furthermore, the invention relates to an article, comprising at least

a first area, consisting of a textile fabric comprising polyamide (PA) and

a second area, consisting of a formed textile fabric comprising polyamide,

wherein the ratio of bending stiffness of the second area and bending stiffness of the first area is at least 1.4, wherein the bending stiffness is determined according to ASTM D5732-95(2001).

[0028] The textile fabric is a woven fabric comprising interlacing threads. The basis weight of the textile fabric in the first area is preferably in the range between 10 and 220 g/m², more preferably 30 and 180 g/m² and the basis weight in the second area is preferably in the range between 10 and 220 g/m², more preferably 30 and 180 g/m². Most preferably, the basis weight of the textile fabric in the first area is essentially the same as the basis weight of the textile fabric in the second area.

[0029] The ratio of the bending stiffness of the second area and the second area may be at least 1.4.

Detailed Description of the Invention

[0030] Details of the invention and advantages are further illustrated with examples, figures and the description of the figures.

Fig. 1a to Fig. 1c

schematically shows an article according to the invention plan view (Fig. 1a) and two cross sections (Fig. 1b and 1c)

Fig. 2

schematically shows the manufacturing step of a dowel (example 11)

[0031] Modification of polyamide (PA) knitted textile fabrics utilizing CaCl₂/EtOH/H₂O as a treatment solution was investigated for different PA fabrics and nonwovens. Treatment with CaCl₂/EtOH/H₂O enables not only physical surface properties like roughness, sorption behavior and also changes of the fiber diameter but according to the invention the modification of the hardness and shape.

[0032] Following polyamide containing textile materials are investigated:

• knitted fabric of 100% polyamide with a fabric density of 110 g/m²
• knitted fabric of 90% polyamide and 10% polyurethane (elastane) with a fabric density of 140 g/m²
• knitted fabrics of 60% polyamide, 30% viscose (regenerated cellulose) and 10% polyurethane (Elastane) with a fabric density of 170 g/m²
• woven fabric of 100% polyamide with a fabric density of 90 g/m²
• warp knitted fabric of 100% polyamide with a fabric density of 80 g/m²
• nonwoven of 60% polyamide and 40% polyethylenterephthalat with a density of 180 g/m²
• nonwoven of 100% polyamide with a density of 180 g/m²
  band (produced by band weaving) of 60% polyamide and 40% polyethylenterephthalat with 13 cm width and 30 g/m density.

[0033] The application of the treatment solution on the fabrics was done using different techniques:

• Samples were immersed in a bath of treatment solution in a ratio sample : solution 1 kg : 10-20 liters. Spraying of the treatment solution with 33 g solvent / 1 m² fabric
• Impregnation by calendaring with a solvent uptake of 1 litre on 1 kg fabric
• Combination of methods described above

[0034] The contact time of the treatment solvent on the fabrics is varied between 1 and 60 min before forming (consolidating) step.

[0035] As treatment solution, the following combinations have been investigated:

CaCl2 / mol%	EtOH / mol%	H2O / mol%
10.00%	20.00%	70.00%
12.50%	18.75%	68.75%
13.33%	13.33%	73.33%
17.16%	20.71%	62.13%
18.00%	12.50%	69.50%
11.11%	11.11%	77.78%

[0036] Bending stiffness was determined following the cantilever method (ASTM D5732-95, 2001). Stripes of approx. 2 cm width and 10 cm length were tested using a fabric stiffness tester Model 112 (Taber Industries, New York, USA). The fabric stripe slowly is pushed over a sharp edge and the stripe starts to bend due to its own weight. When the stripe has reached a bending angle of 41.5 ° the length of the bent fabric stripe is recorded. The length of the bent stripe then is a measure for the stiffness of the sample. Bending was measured for both sides of the fabric (two repetitions each) and the mean value of these four results was calculated.

[0037] The following section describes several examples according to the invention where a textile fabric comprising PA has been treated according to the invention.

Examples

Example 1

[0038] 

Material:	Knitted textile fabric 100% PA
Basis weight:	110 g / m2
Mixing ratio CaCl2: H2O: EtOH (mol%):	12.50: 68.75: 18.75
Solution temperature:	25 ° C
Method:	Immersion with a liquor ratio of 1 kg of goods: 10 liters of solution
Contact time	10 min
Pressure for molding	3 bar by squeezing
Mold temperature:	25 ° C
Washing:	water 4x rinsing (a total of 40 liters of water / kg of goods)
Drying:	120 ° C in a stretched form on a stenter frame
bending stiffness before:	15 mm
bending stiffness after:	26 mm
bending stiffness ratio:	1.73

Example 2

[0039] 

Material:	Knitted textile fabric 100% PA
Basis weight:	110 g / m2
Mixing ratio CaCl2: H2O: EtOH (mol%):	12.50: 68.75: 18.75
Solution temperature:	25 ° C
Method:	Spraying (33 g /m2)
Contact time	1 min
Pressure for molding	3 bar by squeezing
Mold temperature:	25 ° C
Washing:	water 4x rinsing (a total of 40 liters of water / kg of goods)
Drying:	120 ° C in a stretched form on a stenter frame
bending stiffness before:	15 mm
bending stiffness after:	21 mm
bending stiffness ratio:	1.4

Example 3

[0040] 

Material:	Knitted textile fabric 90% PA, 10% elastane
Basis weight:	140 g / m2
Mixing ratio CaCl2: H2O: EtOH (mol%):	12.50: 68.75: 18.75
Solution temperature:	25 ° C
Method:	Immersion with a squeezer with solution uptake of 1 liter solution on 1 kg fabric
Contact time	60 min
Pressure for molding	No additional pressure
Mold temperature:	40 ° C
Washing:	water continuous (15 liters per kg)
Drying:	120 ° C in a stretched form on a stenster frame
bending stiffness before:	15 mm
bending stiffness after:	21 mm
bending stiffness ratio:	1.4

Example 4

[0041] 

Material:	Knitted textile fabric 60% PA, 30% viscose, 10% elastane
Basis weight:	170 g / m2
Mixing ratio CaCl2: H2O: EtOH (mol%):	12.50: 68.75: 18.75
Solution temperature:	25 ° C
Method:	Spraying with a template
Contact time	60 min
Pressure for molding	No additional pressure
Mold temperature:	25 ° C
Washing:	rinsing with water and 1ml/liter acetic acid 80%
Drying:	110 ° C
bending stiffness before:	10 mm
bending stiffness after:	14 mm
bending stiffness ratio:	1.4

Example 5

[0042] 

Material:	Woven textile fabric 100% PA
Basis weight:	90 g / m2
Mixing ratio CaCl2: H2O: EtOH (mol%):	12.50: 68.75: 18.75
Solution temperature:	25 ° C
Method:	Immersion; liquor ratio of 1 kg of goods: 10 liters of solution
Contact time	25 min
Pressure for molding	10 bar by squeezing
Mold temperature:	25 ° C
Washing:	water with water (20 liters / kg) and 1 ml / liter acetic acid (80%)
Drying:	110 ° C
bending stiffness before:	60 mm
bending stiffness after:	118 mm
bending stiffness ratio:	1.96

Example 6

[0043] 

Material:	Warp knitted textile fabric 100% PA
Basis weight:	80 g / m2
Mixing ratio CaCl2: H2O: EtOH (mol%):	11.11: 77.78: 11.11
Solution temperature:	40 ° C
Method:	Immersion; liquor ratio of 1 kg of goods: 20 liters of solution
Contact time	60 min
Pressure for molding	3 bar
Mold temperature:	90 ° C
Washing:	Partially evaporating ethanol and then rising with water
Drying:	Air drying at ambient temperature
bending stiffness before:	40 mm
bending stiffness after:	120 mm
bending stiffness ratio:	3

Example 7

[0044] 

Material:	Nonwoven textile fabric 60% PA, 40% PET
Basis weight:	180 g / m2
Mixing ratio CaCl2: H2O: EtOH (mol%):	12.50: 68.75: 18.75
Solution temperature:	25 ° C
Method:	Dipping and pressing of 1 kg / 1 kg solution
Contact time	5 min
Pressure for molding	10 bar by squeezing
Mold temperature:	60 ° C
Washing:	water 4x rinsing (a total of 40 liters of water / kg of goods)
Drying:	Air drying at ambient temperature
bending stiffness before:	60 mm
bending stiffness after:	520 mm
bending stiffness ratio:	8.66

Example 8

[0045] 

Material:	Textile tape 60% PA, 40% PET, width 13 cm
Basis weight:	30 g / m
Mixing ratio CaCl2: H2O: EtOH (mol%):	17.16: 62.13: 20.71
Solution temperature:	25 ° C
Method:	Immersion, winding on molding tool
Contact time	45 min
Pressure for molding	10 N tape tension upon winding
Mold temperature:	45 ° C
Washing:	water 4x rinsing (a total of 40 liters of water / kg of goods)
Drying:	Air drying at ambient temperature
bending stiffness before:	100 mm
bending stiffness after:	350 mm
bending stiffness ratio:	3.50

Example 9

[0046] 

Material:	Nonwoven textile 100% PA
Basis weight:	180 g / m2
Mixing ratio CaCl2: H2O: EtOH (mol%):	17.16: 62.13: 20.71
Solution temperature:	25 ° C
Method:	Dipping / pressing 1 kg solution / 1 kg material
Contact time	5 min
Pressure for moldig	Pressing, 10 bar using a molding tool
Mold temperature:	30 seconds 40 °C then 20 seconds 90 °C by hot vapor
Washing:	water rinsing (40 liters of water / kg of goods)
Drying:	Air drying at ambient temperature
bending stiffness before:	60 mm
bending stiffness after:	120 mm
bending stiffness ratio:	2

Example 10

[0047] 

Material:	Nonwoven 100% PA
Basis weight:	180 g / m2
Mixing ratio CaCl2: H2O: EtOH (mol%):	17.16: 62.13: 20.71
Solution temperature:	25 ° C
Method:	Immersion / pressing on 2 kg solution / 1 kg product
Contact time	5 min
Pressure for molding	Pressing, 10 bar using a molding tool
Mold temperature:	80° C for 5 min
Washing:	water rinsing (40 liters of water / kg of goods)
Drying:	Air drying at ambient temperature
bending stiffness before:	60 mm
bending stiffness after:	320 mm
bending stiffness ratio:	5.33

Example 11: on-site production of anchor fitting (see Fig.2)

[0048] 

Material:	Knitted textile fabric 100% PA
Basis weight:	110 g / m2
Mixing ratio CaCl2: H2O: EtOH (mol%):	12.50: 68.75: 18.75
Solution temperature:	25 ° C
Method (see Figure 2)	Inserting the fabric into a hole
	Spraying the same amount of solvent into the hole
	Screwing the immersed fabric with a screw
Contact time	10 min
Pressure for molding	No additional pressure
Mold temperature:	25 ° C
Washing:	4x spraying with water
Drying:	Air pistole at ambient temperature
	Unscrew the screw

[0049] Fig. 1a to 1c shows an article according to the invention in plain view, comprising a first area 10, consisting of a textile fabric comprising polyamide (PA) and a second area 20, consisting of a formed textile fabric comprising polyamide. The basis weight of the textile fabric in the first area is 110 g/m² and the basis weight in the second area is identical with 110 g/m². The bending stiffness of the first area is 15 mm and the bending stiffness of the second area is 26 mm determined according to ASTM D5732-95(2001).

[0050] Hence, the ratio of the bending stiffness of the second area and the second area is 1,73.

[0051] The first area is flowing and has no dimensional stability, the second area is three dimensional stable. In the present example, the second area is formed by embossing the letters "TEXT". This may e.g. be used to integrate stable structures in a fabric.

[0052] Fig. 2 shows the manufacturing steps of a dowel according to the invention.

[0053] First in step (a) a textile fabric comprising polyamide (PA) is provided and inserted into a wall.

[0054] In step (b) the textile fabric is treated with the treatment solution according to example 11, according to which the treatment solution is a mixture of CaCl₂, EtOH and H₂O, wherein the CaCl₂ content is 12.5 mol%, the EtOH content is 18.75 mol%, the molar ratio between CaCl₂ : EtOH : H₂O is 1 : 1.5 : 5.5 and the H₂O/EtOH molar ratio is 3.67. The treatment solution is sprayed onto the fabric for ca. 5 s.

[0055] Next, in step (c) the treatment solution is squeezed from the fabric by a screw to adjust the solvent content in the fabric. Simultaneously step (d) is performed by consolidating the textile fabric for 10 minutes while the textile fabric is still containing the treatment solution by adjusting the temperature of the textile fabric to a temperature of 25 °C with thereby forming the textile fabric in the desired three-dimensional structure.

[0056] In step (e) the treatment solution is quenched while the formed textile fabric still contains treatment solution by adding water, followed by air dying at ambient temperature.

[0057] Finally, the formed textile fabric is obtained by unscrewing the screw followed by washing and drying (step (f)).

Claims

1. Method for manufacturing a three-dimensional formed structure from a textile fabric, comprising the steps of

(a) providing a textile fabric comprising polyamide;

(b) contacting the textile fabric with a treatment solution wherein the treatment solution comprises a mixture of CaCl₂, EtOH and H₂O, wherein the CaCl₂ content is > 6 mol%, the EtOH content is < 25 mol%, the molar ratio between CaCl₂ : EtOH : H₂O is between 1 : 0.6 - 2 : 3.4 - 7 and the H₂O/EtOH molar ratio is > 2.5. for at least 1 second and at most 4 hours by immersion or for at least 1 s and at most 5 minutes by spraying;

(c) squeezing of the treatment solution from the fabric to adjust the solvent content in the fabric;

(d) consolidating the textile fabric for 1 s to 60 minutes while the textile fabric is still containing the treatment solution by adjusting the temperature of the textile fabric to a temperature of between 10 °C to 120 °C with the provision that the temperature is at least 100 °C below the melting point of the polyamide and by forming the textile fabric in the desired three-dimensional structure;

(e) quenching the treatment solution while the formed textile fabric still contains treatment solution by adding water and/or by evaporating ethanol out from the fabric; and

(f) obtaining the formed textile fabric followed by washing and drying.

2. Method according to claim 1, wherein the polyamide is an AB polymer, an AA/BB polymer or a mixture thereof, wherein the AB polymer comprises the following structure units -[NH-(CH₂)_x-CO]_n- and the AA/BB polymer comprises the following structure units -[NH-(CH₂)_x-NH-CO-(CH₂)_y-CO]_n-.

3. Method according to claim 1 or claim 2, wherein the polyamide is of type PA 6.6.

4. Method according to one of claims 1 to 3, wherein the contacting step (b) of the textile fabric in the treatment solution of CaCl₂/EtOH/H₂O is carried out for approximately 3 minutes.

5. Method according to one of claims 1 to 4, wherein the molar ratio between CaCl₂: EtOH : H₂O is preferably between 1 : 1.5 : 3.5.

6. Method according to one of claims 1 to 5, wherein the contacting step (b) of the textile fabric in a treatment solution of CaCl₂/EtOH/H₂O is for at least 5 s and at most 5 minutes, immediately followed by quenching the treatment solution by adding water and/or evaporation of ethanol.

7. Method according to one of claims 1 to 6, wherein forming includes applying a pressure of between 0,1 bar and 100 bar.

8. Method according to one of claims 1 to 7, wherein only a selected part of the textile fabric comprising polyamide is formed.

9. Textile fabric comprising a three-dimensional formed structure obtainable by a method according to one of claims 1 to 8.

10. Article, comprising at least

a first area, consisting of a flexible textile fabric comprising polyamide (PA) and

a second area, consisting of a formed textile fabric comprising polyamide,

wherein the ratio of the bending stiffness of the second area to the first area is at least 1.4, wherein the bending stiffness is determined according to ASTM D5732-95(2001).

11. Article according to claim 10, characterized in that the first area and the second area are connected without any further joining steps.

12. Article according to claim 10 or claim 11, characterized in that the basis weight of the textile fabric in the first area is in the range between 10 and 220 g/m², preferably 30 and 180 g/m² and the basis weight in the second area is in the range between 10 and 220 g/m², preferably 30 and 180 g/m².

13. Article according to claim 12, characterized in that the basis weight of the textile fabric in the first area is essentially the same as the basis weight of the textile fabric in the second area.

14. Use of a textile fabric according to claim 9 or article according to one of claims 10 to 13 as a bag, a lampshade, a dowel, a protective cover for body parts, in sport clothing.

Drawing